Our home built ins 1970, we purchased a new roof July 2008 (recent) they told us we did not have a soil stack through the roof... scaring us about methane gas build up, etc. we have lived in the house since 1996 and we have not blown up yet... is there a circumstance that a home would not need a soil stack venting out of the roof top? How do we go about researching this before we panic and perhaps spend money not necessary to install this? Thank you for any advice or direction you can give me.

OK, don't panic. You haven't blown up yet so you are not likely to.

First, the only house that shouldn't have a sewer stack would be one that doesn't have indoor plumbing. Sewer gas is or can be methane but it's not concentrated enough to cause an explosion, just bad odors.

The sewer system has a lot of bad smelling odors and gases in it as you can imagine. Look under you kitchen of lavatory sink. Look at the drain pipe, you will see a "trap", that place where the pipe comes down then goes back up a little bit. That was put there to hold water when the sink is not being used. The water blocks the odors and gas from coming into your house. As water flows down a pipe it pulls air behind it. There must be a place for air to come in or the water going down the pipe would pull all of the water out of the trap. Therefore a special "vent" pipe is put in for air to enter the drain system. To keep odors out of the house the pipe must go to the outside. That"s your sewer stack.

Go outside and look at your roof above the bathroom. You should see pipe about 3" in diameter sticking up. There should be another smaller one above the kitchen.

If you don't see these go up in the attic and look for them there, above the bathroom and above the kitchen. Take note of their size and the type of pipe, PVC (white plastic), ABS (black plastic), cast iron (thick dull colored metal), galvanized (silver colored metal) or copper.

Don't fall through the attic and let us know what you find.

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Thank you for the information. However, we only have the furnace stack on the roof and a cover which is over the bathroom fan. Are you saying this soil stack could be venting in the attic and just not through the roof? We have never been in the attic as electricians in the past said if we did go up there to be careful of exposed electrical... how fun is that to think about. Are attic can be accessed through the attached garage so I will get a ladder and have hubby hold it and with flash light take a quick peak and hopefully not go in there... we do not have a fan in the kitchen, nor a hooded stove... many quirks about this old house..

If by exposed wiring the electrician meant bare or uninsulated wiring, you should have told hin to get his blankety blank up there and fix it. More likely a scare tactic, house would have to really, really, be old to have that.

How old is house? Yes the soil stack probably ends in the attic. Must have a well vented attic to not have odors.

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Our house was built in 1970. We have lived there since 1996. Never smells or anything. Just the two of us. There are screens over the vents on either end of the house in the attic. Of which need to be replaced as I see holes in them letting the bees, wasps, etc. in and out. This is a 960 sq ranch with basement. Unfortunately that electrician passed away, but I remember him saying he capped off the exposed up there but much wiring of course from ceiling fans, overhead lighting in kitchen, etc. I am sure...

Alexjackmo, please make responses by using "Post Quick Answer" so all can see.

Built in 1970 is not really old. I was built long before that and I'm still of sound mind and body. Well body anyway.

The type of wiring, uninsulated wiring, goes back long before that. Goes back so far that I have never really seen it and I'm older than dirt. Thought you were talking about something built around 1900. Not to fear about exposed wiring.

Check the attic for pipes. Walk on walk boards or step on ceiling joist. You will probably find a 3" cast iron pipe above bath area and a 2" galvanized for kitchen. Fix will be a Saturday task if you are a decent handyman/person.

Thank you so much for all your help. My husband is certainly not a handyman and I am the fixer upper... he is actually afraid to go in the attic so guess what, that will be me... I will be careful, but if I do not see the vents I will just hope that we can do without them...

Well if you have to do it, he better be prepared to take you out to dinner, an expensive dinner, maybe a show also.

Our home built ins 1970, we purchased a new roof July 2008 (recent) they told us we did not have a soil stack through the roof... scaring us about methane gas build up, etc. we have lived in the house since 1996 and we have not blown up yet... is there a circumstance that a home would not need a soil stack venting out of the roof top? How do we go about researching this before we panic and perhaps spend money not necessary to install this? Thank you for any advice or direction you can give me.

I am hoping someone else will see this as there is nothing in the attic?? If we have never had anything but the furnace flue why do we need a soil stack now?? AND what kind of costs could be involved? Who do we call?

Have a plumber look and give estimate. You have to have vents (soil stack) or plumbing would not work. They have to end somewhere, if not in attic may be in walls. I've heard of plumbers not going through roof but never ending in walls. They are probably in attic, just covered with insulation. Not a particularly big job to extend through roof.


OK - now I understand why I couldn't find a no-hub PVC combination wye and what to do about it. Great suggestion on the root killer too; thanks. Best Regards,


Your answers don't have the "Rate this Answer!" field but mine do - how do I rate your answer?

I have our plumber coming over today, Monday, Aug 4th... he said if he extends through the roof the cost is $500.00. Hope that is reasonable... we have had him for years... we will be eating creamed corn over bread this month, but want to be safe... wish us luck...

Not unreasonable. Kind of depends on how hard it will be to get to pipes. Pipes probably close to eave of house and be a lot of crawling around and not much head room. A little high but not unreasonable.

What City are you in ?

I am located in Akron, Ohio. Just paid our Plumber $500... he looked liked a ghost first time out of that attic. He was covered with insulation dust and hotter than you can guess. He found the waste pipe it was just slightly vented through the attic, however, covered completely with insulation. Once the roofers installed the new roof all venting caps were removed and replaced with ridge vent. That is when we began to smell the sewer gases, or whatever. Our plumber is coming back today to actually extend the pipe through the roof, flash and do what he does to get us safe from the gases. Thanks to all for responding.

Remember there should be two vents. I say should be.

There is only one vent coming through the roof now not counting the Furnace Flue... Fred did not say anything about another vent that we would need?? Hopefully you are referring to the Furnace Flue as one vent and now the Soil Stack the second... uh, oh, here we go again??

Amazing!
Did the roofers cut the vents off in the attic or was it originally done that way?

Usually there are at least two "soil stacks".
3-inch for the toilets and bathroom and a 1-1/2 or 2-inch for the kitchen.
Perhaps they all connect to the 3-inch main stack.

Your plumber will do what has to be done to make it right.

No need to be afraid of electrical wires. They should all be well insulated in their insulated jackets.
If concerned, turn off the electrical power to your house at the circuit breaker or fuse box.